My I/O is a:
- 2008 Volvo Penta 5.7 Gi-Gf 300 hp
- DP-SM (SX duo-prop)
I piloted my boat to the boat yard to get some work done. It ran well as it always has, and aside from a noisy pulley there were no issues with the inboard.
I normally do the annual service myself but because I plan to take it quite far this year I thought I’d get a professional marine mechanic to do the work instead.
On the inboard I requested:
- the inboard be given a general service (oils, filters)
- the pulley be replaced
- the serpentine belt be replaced
On the out drive I requested:
- the tilt cylinders be replaced with the new Volvo Penta ones I’d purchased.
- the props be repaired and replaced.
Following the service, when I put the boat back in the water the following was immediately apparent (it ran rough-as-guts)
He said it was nothing he could have done given the scope of the work.
He checked the distributor cap, found it to be quite corroded and so I agreed to replace it along with all cables and spark plugs.
He did a compression test too which reported great results, all units at 170-180 psi.
Unfortunately the replacement of the ignition parts did not improve the performance of the boat and it is still running terribly.
The mechanic now thinks it might be the coupler that connects the out drive to the inboard.
I’d appreciate anyone’s thoughts about possible cause.
Is there anyway a coupler or misalignment of shaft cause the issues described? Eg. Could removing tilt cylinders cause a misalignment?
Based on the work performed can anyone see a likely cause?
To me it feels like I had a boat that was running great. It needed a little work sure, but nothing serious and no reason to think it could affect the general performance. The mechanic is still attempting to troubleshoot.
Any advice is greatly appreciated.
- 2008 Volvo Penta 5.7 Gi-Gf 300 hp
- DP-SM (SX duo-prop)
I piloted my boat to the boat yard to get some work done. It ran well as it always has, and aside from a noisy pulley there were no issues with the inboard.
I normally do the annual service myself but because I plan to take it quite far this year I thought I’d get a professional marine mechanic to do the work instead.
On the inboard I requested:
- the inboard be given a general service (oils, filters)
- the pulley be replaced
- the serpentine belt be replaced
On the out drive I requested:
- the tilt cylinders be replaced with the new Volvo Penta ones I’d purchased.
- the props be repaired and replaced.
Following the service, when I put the boat back in the water the following was immediately apparent (it ran rough-as-guts)
- loss of power - 4,000 revs plus and only 5 knots. Normally 3,000 revs get it on a plane and up to 20 knots within seconds.
- the revs were all over the place - without touching the throttle it will jump around up and down between 1,200 to 2,500+ revs.
- at idle the boat is at 1,200 revs - higher than before
- very rough, spluttering sound
- often close to stalling
- regular backfiring
- entire engine block shaking
- slow to start up
- noisy rough feeling steering
He said it was nothing he could have done given the scope of the work.
He checked the distributor cap, found it to be quite corroded and so I agreed to replace it along with all cables and spark plugs.
He did a compression test too which reported great results, all units at 170-180 psi.
Unfortunately the replacement of the ignition parts did not improve the performance of the boat and it is still running terribly.
The mechanic now thinks it might be the coupler that connects the out drive to the inboard.
I’d appreciate anyone’s thoughts about possible cause.
Is there anyway a coupler or misalignment of shaft cause the issues described? Eg. Could removing tilt cylinders cause a misalignment?
Based on the work performed can anyone see a likely cause?
To me it feels like I had a boat that was running great. It needed a little work sure, but nothing serious and no reason to think it could affect the general performance. The mechanic is still attempting to troubleshoot.
Any advice is greatly appreciated.
